Heretofore, a variety of devices have been employed to adapt conventional cameras and video cameras for underwater use. Still other devices have been developed which, to some extent, enable such electronic equipment to be used in inclement weather conditions or in environments otherwise hostile to the equipment such as the beach, for example. The subject invention provides a means for accomplishing each of these ends.
A review of the prior art reveals two general categories of waterproofing devices within which electronic equipment may be placed for protection. The first species share in common the employment of a rigid pressure hull or chamber adapted with external controls which are connected to and operate the camera held within the chamber. Such devices suffer from various shortcomings, namely they are bulky, overly complex in both structure and operation, and are cost prohibitive for the amateur photographer and even some professionals.
These shortcomings associated with rigid equipment vessels resulted in the development of the second species of protective devices which are generally comprised of a flexible bag-like enclosure with optical windows against which the camera's viewfinder and lens are to be placed. Such devices allow the user to operate the cameras controls through the surrounding flexible bag which is typically fabricated of a clear plastic material to facilitate this purpose.
One of the earliest references relating to this latter species of protective device is U.S. Pat. No. 1,535,312 issued to Hosking in 1925 which teaches a waterproof covering for cameras. The device consists of a flexible waterproof bag-like covering having draw strings at the bottom thereof for closure purposes. One serious limitation of this relatively simplistic device is that it requires the user to keep the camera upright when used underwater to prevent the entrance of water through the bag opening. In one embodiment, the Hosking reference teaches the use of a sash-like window against which the camera lense is placed.
In 1962, U.S. Pat. No. 3,026,784 was issued to Byers for an underwater photography enclosure with the open end of the bag being sealed, allowing a volume of entrapped air to remain such that the apparatus as a whole could float for purposes which are obvious. Similarly, U.S. Pat. No. 3,042,796 issued to De Forest in 1962 teaches a bag closing means similar to that disclosed in Byers and also teaches the entrapment of air for buoyancy purposes. The problem with each of these references and bag-like enclosures generally, however, is that any significant amount of entrapped air between the camera and the bag will make it more difficult to locate and operate the control buttons of the camera.
This problem was slightly corrected by U.S. Pat. Nos. 5,087,934 and 5,239,323, each issued to Johnson in 1992 and 1993 respectively, which teach a waterproof and flexible semi-rigid housing shaped to roughly conform to the shape of the camera equipment contained therein. By providing a camera-shaped bag rather than a conventionally shaped one, the Johnson device reduced the amount of entrapped air within the system, however, the shape of the enclosure could not be universally applied to all video cameras which are of different sizes and shapes and which may have viewfinders in different locations.
Finally, U.S. Pat. No. 4,771,299 issued to Gell, Jr. in 1988 teaches the use of a flexible waterproof container and a means of pressurizing the container so that the equipment may be used at greater depths by preventing the collapse of the flexible material and its molding around the camera under pressure.
Each of the above described references share in common the entrapment of air within the enclosure, whether incidentally as a result of their construction, or intentionally for the purpose of pressurizing the system for buoyancy or use at greater depths. Applicant has discovered that the exact opposite characteristic is desirable, namely providing an enclosure system which is relatively devoid of air. By withdrawing air from the system before closure, applicant has discovered a means of obviating those shortcomings associated with the prior art.